AP Psychology: Scientific Foundations & Biological Bases of Behavior

Comprehensive AP Psychology vocabulary flashcards covering key definitions, concepts, researchers, and neural mechanisms across Unit 1 (Scientific Foundations of Psychology) and Unit 2 (Biological Bases of Behavior).

Empiricism

The view that knowledge originates in experience and that science should, therefore, rely on observation and experimentation.

Structuralism

An early psychological perspective founded by Wilhelm Wundt that emphasized units of consciousness and the identification of elements of thought using introspection.

Functionalism

An early psychological perspective associated with William James that was concerned with how an organism uses its perceptual abilities to adapt to its environment.

Behavioral Approach

A psychological perspective concerned with behavioral reactions to explicit environmental stimuli and learning through conditioning, championed by John B. Watson and B.F. Skinner.

Psychoanalytic Approach

A psychological perspective founded by Sigmund Freud that emphasizes how unconscious instincts, motives, defenses, and early childhood experiences shape adult personality and behavior.

Humanistic Approach

A psychological perspective associated with Carl Rogers and Abraham Maslow that focuses on individual potential for growth, unique self-concept, and the motivation to self-actualize.

Operational Definition

A detailed description of the precise procedure and measurable characteristics used to determine the presence of a variable, allowing other researchers to replicate the study.

Independent Variable (IV)

The factor that a researcher directly manipulates in a controlled experiment to observe its effect; represents the hypothesized cause.

Dependent Variable (DV)

The specific behavior or mental process measured in an experiment or quasi-experiment; represents the hypothesized effect.

Confounding Variable

A factor other than the independent variable that may produce an unintended effect on the dependent variable, often arising from pre-existing group differences.

Random Selection

The procedure of choosing members from a target population such that every individual has an equal chance of being selected, maximizing sample representativeness and generalizability.

Random Assignment

The process of dividing a sample into experimental and control groups so that every participant has an equal probability of being placed in any condition, reducing potential confoundings.

Single-Blind Procedure

An experimental research design in which participants are unaware of whether they are placed in the experimental group or the control group.

Double-Blind Procedure

An experimental research design in which neither the experimenter nor the participants know who has been assigned to the experimental group or the control group.

Placebo Effect

A change or response in behavior resulting from a participant's belief in the treatment's effectiveness rather than from any active ingredient of the independent variable.

Correlation Coefficient

A statistical index ($r$) measuring the strength and direction of a relationship between two variables, ranging from $-1.0$ to $+1.0$.

Descriptive Statistics

Numerical measurements used to organize, summarize, and present a specific set of research data collected from a sample.

Inferential Statistics

Statistical procedures used to interpret sample data, test hypotheses, and make predictions or generalizations to a larger population.

Statistical Significance

A statistical criterion (p \text{ value} \thinspace \text{\textlequal} \thinspace 0.05) indicating a high probability that the independent variable produced the observed difference and that the results were unlikely caused by chance.

Informed Consent

An ethical requirement enforced by Institutional Review Boards (IRBs) requiring researchers to inform participants of study procedures, risks, and benefits, and securing agreement to participate without penalty for withdrawal.

Genotype

The entire structural combination of inherited genes within an individual's genetic makeup.

Phenotype

The observable physical and behavioral traits expressed by an organism as a result of its genotype interacting with the environment.

Heritability

The mathematical degree of variance among individuals within a population that can be attributed to inherited genetic differences.

Environmentality

The degree to which the expression of a characteristic or trait is influenced by the environmental context in which an organism lives.

Adaptive Traits

Specific inherited physical or behavioral variations that enhance an organism's chances of survival and reproduction in a specific environment.

Endocrine System

A ductless gland system that releases chemical messengers called hormones into the bloodstream to regulate body functions slowly over minutes, hours, or weeks.

Pituitary Gland

Known as the 'master gland,' a forebrain structure below the hypothalamus that secretes growth hormone, prolactin, and oxytocin, while signaling other glands to release hormones.

Myelin Sheath

A layer of fatty tissue produced by glial cells surrounding the axon of some neurons that insulates the axon and increases the speed of action potentials; its loss causes multiple sclerosis (MS).

Action Potential

A brief electrical charge (depolarization) that travels down an axon when sodium ($\text{Na}^+$) ions enter the cell membrane and potassium ($\text{K}^+$) ions move outside.

Resting Potential

The resting, polarized state of a neuron during which the fluid interior of the axon maintains a negative charge relative to the positively charged exterior fluid.

Refractory Period

The resetting period during repolarization when the sodium-potassium pump restores original ion positions, preventing the neuron from firing another action potential.

Synapse

The extremely narrow gap (synaptic cleft) between the terminal button of a sending neuron and the receptor site of a receiving dendrite where neurotransmission occurs without physical contact.

Agonist

A drug or chemical that enhances neurotransmitter activity by fitting postsynaptic receptor sites to excite the cell or by delaying neurotransmitter reuptake (e.g., Xanax, Prozac).

Antagonist

A drug or chemical that occupies receptor sites on a postsynaptic neuron without triggering a response, blocking the natural neurotransmitter from binding (e.g., antipsychotic drugs).

Dopamine

A neurotransmitter regulating reward, pleasure, voluntary movement, learning, and attention; deficits lead to Parkinson's disease, while excess activity is linked to schizophrenia.

Acetylcholine (ACh)

A neurotransmitter critical for memory and muscle movement; shortages are linked to Alzheimer's disease or paralysis, while excessive levels cause muscle convulsions.

Serotonin

A neurotransmitter regulating mood, appetite, and sleep; deficits are associated with depression, feeding disorders, sleep-wake disorders, and aggression.

GABA

The primary inhibitory neurotransmitter involved in relaxation and sleep; shortages are linked to anxiety disorders, seizures, and insomnia.

Medulla

A primitive hindbrain structure located below the pons that governs vital automatic survival functions like heartbeat, breathing, and digestion, as well as reflexes like coughing and sneezing.

Cerebellum

A hindbrain structure ('little brain') situated behind the brainstem that manages balance, movement coordination, fine motor skills, and procedural memory.

Reticular Formation

A midbrain network of nerves extending through the brainstem to the thalamus that regulates arousal, sleep, attentiveness, and sensory filtering; damage leads to a coma.

Thalamus

A pair of forebrain structures situated atop the brainstem that functions as a sensory relay center, receiving and directing all incoming sensory data (except smell) to the cerebral cortex.

Hippocampus

A limbic system structure surrounding the thalamus essential for explicit memory formation and learning.

Amygdala

An almond-shaped limbic structure situated at the end of each hippocampal arm that processes emotions, particularly fear and aggression.

Hypothalamus

A limbic system structure below the thalamus that regulates internal maintenance functions (eating, drinking, temperature, sex), controls the autonomic nervous system, and manages the endocrine system via the pituitary gland.

Corpus Callosum

A wide bundle of neural fibers connecting the left and right cerebral hemispheres, enabling cross-hemispheric communication and data transfer.

Broca's Area

A region located in the left frontal lobe that controls facial motor movements needed for speech production; damage causes expressive aphasia.

Wernicke's Area

A structure located in the left temporal lobe responsible for language comprehension and creating meaningful speech; damage causes receptive aphasia.

Neuroplasticity

The brain's ability to modify its structure and reorganize neural pathways throughout life to adapt to new experiences, learning, or damage.

Electroencephalogram (EEG)

A noninvasive brain scanning tool using scalp electrodes to detect and record electrical wave patterns of neurons, used to evaluate sleep stages and seizures.

Positron Emission Tomography (PET)

A functional neuroimaging technique tracking radioactive glucose consumption in the blood to depict color-coded active brain regions during cognitive tasks.

Functional Magnetic Resonance Imaging (fMRI)

A noninvasive scanning technique measuring real-time oxygenated blood flow to track both brain structure and dynamic function without radiation exposure.

Circadian Rhythm

A regular bodily biological cycle operating on an approximate 24-hour schedule, governing sleepiness and body temperature via the suprachiasmatic nucleus (SCN).

REM Sleep

Rapid eye movement sleep (paradoxical sleep) characterized by rapid wave patterns, darting eye movements, elevated heart rate, muscle paralysis, and vivid dreams.

Manifest Content

According to Sigmund Freud, the literal, consciously remembered storyline and events of a dream.

Latent Content

According to Sigmund Freud, the hidden, underlying psychological meaning and symbolic wishes contained within a dream.

Tolerance

The diminishing effect of a drug following repeated exposure, requiring the user to consume larger doses to achieve the initial drug effect.

Withdrawal

The physical discomfort and psychological distress that follow the abrupt discontinuation of a drug to which an individual has developed physical dependence.